Alpha glucosidase is an enzyme present in the body that hydrolyzes the α-1,4-glycosidic linkage of disaccharides and polysaccharides to form monosaccharides such as glucose, which can then be used for energy. While glucose and other monosaccharides are necessary for life, they can also cause undesired effects when they are not present in exactly the right amount. For example, it has long been known that monosaccharides such as glucose react with free amino groups on the skin surface to form certain intermediates that begin a cascade of reactions that ultimately results in an irreversible crosslinking of skin proteins such as collagen. Crosslinking of collagen in turn contributes to the wrinkling and senescence of skin with age. The metabolites generated during the reaction cascade are often referred to as advanced glycation endproducts (AGE). The AGE's are a heterogeneous and complex mixture of compounds that have been shown to play a role in skin aging. Further, it has been shown that individuals with diabetes have skin proteins with increased crosslinking when compared to non-diabetic individuals, presumably because the increased presence of glucose in their skin and body tissues results in formation of AGE in their skin. For that reason, if something inhibits the ingredients that contribute to formation of AGE's it will have a positive impact on the occurrence of skin protein crosslinking and its resulting negative effects on skin. One way to inhibit formation of AGE's in skin is to treat the skin with ingredients that inhibit α-glucosidase, so that the carbohydrates, disaccharides, and 1,4 polysaccharides on the skin surface are not readily metabolized into their constituent sugars. This in turn ensures that fewer such monosaccharides are present on the skin surface to contribute to the formation of AGE's.
Accordingly it is an object of the invention to provide a cosmetic composition for treating skin, or other keratinous surfaces such as nails or hair, containing at least one α-glucosidase inhibitor.
It is a further object of the invention to provide a composition for treating skin containing at least one α-glucosidase inhibitor, wherein said composition is substantially free of monosaccharides and/or other complex sugars capable of reducing to simple sugars such as glucose or sucrose or both.
It is a further object of the invention to provide a method for ameliorating the adverse effects of aging or sun damage on skin, or cosmetically treating skin for improvement, comprising applying to the skin a cosmetic composition containing at least one α-glucosidase inhibitor.
It is a further object of the invention to provide a skin treatment regimen or process comprised of treating skin with at least two products selected from cleanser, toner, and leave-on skin treatment composition, wherein at least one of the products used in the process contains at least one α-glucosidase inhibitor, and preferably, wherein at least one of the products is substantially free of monosaccharides, or di- or polysaccharides that contain at least one α-1,4-glycosidic linkage operable to hydrolyze, to form simple sugars or monosaccharides.
It is a further object of the invention to provide a kit for treating skin comprised of at least two products selected from cleanser, toner, and at least one leave on skin treatment composition wherein one or more, preferably all of the products are free of monosaccharides, or polysaccharides capable of hydrolyzing to form monosaccharides, and wherein at least one product in the kit components contains at least one α-glucosidase inhibitor.